Vikunja has Cross-Project Information Disclosure via Task Relations — Missing Authorization Check on Related Task Read

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-33676: 0.36% estimated exploitation activity in the next 30 days; percentile 30.11 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary When the Vikunja API returns tasks, it populates the relatedtasks field with full task objects for all related tasks without checking whether the requesting user has read permission on those tasks' projects. An authenticated user who can read a task that has cross-project relations will receive full details (title, description, due dates, priority, percent completion, project ID, etc.) of tasks in projects they have no access to. Details The vulnerability is in addRelatedTasksToTasks() at pkg/models/tasks.go:496-548. This function is called by addMoreInfoToTasks() (line 773) during every task read operation — both project task listings (GET /api/v1/projects/{id}/views/{id}/tasks) and single task reads (GET /api/v1/tasks/{id}). The function fetches all related tasks directly from the database without any permission filtering: The a web.Auth parameter is received but only used for determining favorites (line 519), never for access control on the related tasks themselves. In…

Published by the source

25 Mar 2026, 21:17 UTC

Last modified by the source

25 Mar 2026, 21:17 UTC

Source last checked

26 Oct 2026, 15:18 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8cmm-j6c4-rr8v

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# Patch Next advisory brief: CVE-2026-33676

Advisory: Vikunja has Cross-Project Information Disclosure via Task Relations — Missing Authorization Check on Related Task Read
IDs: CVE-2026-33676, GHSA-8cmm-j6c4-rr8v
Record: https://patchnext.com/advisories/cve-2026-33676 (revision 1, source checked 26 Oct 2026, 15:18 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: code.vikunja.io/api 2.2.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go code.vikunja.io/api: affected <= 2.2.0; fixed in 2.2.1

## Suggested inspection (read-only)
- Go code.vikunja.io/api: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on code.vikunja.io/api.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8cmm-j6c4-rr8v (GitHub-reviewed advisory GHSA-8cmm-j6c4-rr8v lists affected ranges: Go code.vikunja.io/api >=0 <=2.2.0)

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